Limits and overage rates

Sending limits, rate limits, and overage pricing for the Paubox Email API.

Sending limits

Limit	Value
Max recipients per message	100
Max attachment size (total per message)	50 MB
Bulk messages (recommended max per request)	50

For high-volume sends, use the bulk messages endpoint rather than looping over individual /messages calls. Paubox recommends batches of 50 or fewer messages per request.

If you receive a 429 Too Many Requests response, back off and retry. See Errors for retry guidance.

What to do if you’ve reached your limit

You will be charged a small amount per-email for each email that you send beyond the limit of your current plan. Any overage charges will appear on an invoice of the month after any over-limit sending occurs.

Paubox Email API overage costs

If you go over your plan limits, here’s a breakdown of the overage costs you’ll incur:

Plan Information	Monthly Plan Limits	Cost Per Extra Email
Free	300	-
Pro	10,000 emails	$0.0130
Pro	30,000 emails	$0.0130
Pro	50,000 emails	$0.0100
Pro	100,000 emails	$0.0098
Pro	Custom	-